Hello,
I've been driving a '92 2.3 liter 4 cylinder engine. It is at 149,500 miles right now and I've put 16,000 on it since I bought it 1.5 years ago.

It runs well etc. I get an oil change done every 3K, I use fuel injector cleaner every 3K, I just changed out all the spark plugs and most recently I used Seafoam to clear out the system, so to speak.

I have been experiencing some incredibly rough driving off and on since I've purchased it. At first it was only once every month or so. In the past month is has been even more frequent and in the past week it has been almost every day. It usually only drives like this on days where it is most humid out and this week it has been raining everyday (just a little too warm to freeze). I've checked the RPM's and they are consistent and the clutch is new so I know the transmission is not slipping.

I've been hearing different theories as to why it is doing this but I have yet to come across a simple, concrete solution. If I drive the truck long enough the dough driving stops - and it drives A-OK for the rest of the trip.

Any help would be appreciated!

Sounds like a bad head gasket, or possibly a cracked head.


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99 XLT Super Cab 4.0 OHV - Manual - 4wd - Live Axle Conversion - Interior & Exterior LEDs - Mustang Dome
97 XLT Regular Cab 2.3 - Auto - 2wd (R.I.P)

Is there any way for me to verify that this is the cause?

It only seems to do it when there is a lot of humidity.

exhaust/pressure test the coolant system.

but unless you have other symptoms (over heating, extra dirty coolant, milky oil, coolant loss, etc) I don't know why you would lean that way.

Sounds more like a vacuum leak to me, but without more information, its hard to say. I would probably do some basics, such as, if you have not replaced the spark plugs, and don't know how old they are, I would do some basic maintenance, replace plugs, run some fuel injector cleaner through it, replace your fuel filter, replace plug wires, replace the air filter, etc. Just make sure everything is up to snuff. Check under the hood for anything loose/cracked.

If you want to pressure test the cooling system, that can be done for free if you live near a parts store, most will rent you a pressure tester. and you can check for exhaust gases in the coolant as well, but that costs a few dollars as they will rent you the equipment, but you'll have to buy the fluid.

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98 Mazda B4000 4x4 31" tires
Check out my off road youtube channel: https://www.youtube.com/c/aicoffroadvideo

you mentioned a vac leak ^^^ made me think of having an egr valve stick open. BUT i'm not sure if the 92 year models had egr or not!

OP, i see you got plugs done, i guess that made no difference? and did you do the plug wires like aroundincircles mentioned?
wonder if you've got screwy coil packs...

edit: and check the brake booster vac line (goes from the brake master cyl to teh intake) for a crack, I seen it happen! keep us posted

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just though of something else, i had a 'sudden low power' situation that would reslove itself within seconds... not exactly like you are experiencing, i know. It was a clogged fuel filter. that's a cheap one to rule out

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1999 xlt 2.5l 5-speed Supercab 159k
83 diesel 2.2l na
06 F250 6.0l psd
{click for lol}

I might be able to check the coolant this weekend. I did have to add coolant this past week because I was extremely low, but I have not seen any leakage since. So I'm not sure what was up with that.

I have new spark plugs, I do regular maintenance as well. I also had the brake lines AND ABS unit replaced this past August, so I'm not sure if there would be any leakage from the Brake booster vac lines (not sure if those are related). Plus, I just replaced the fuel filter 1 month ago.

Is this something that HAS to be fixed if it seems like it only really does it when its really humid out? As soon as I get it into 4th gear (sometimes 5th) the rough driving goes away. Every time. I'm not trying to hold onto this truck beyond this summer - so I'm hoping not to put a lot of money into it if it can be helped.

well, coolant loss can be a sign of a bad head gasket, and it can be expensive to replace, and they tend to have a slow leak at first, and then really fail in a cloud of steam on the side of the highway, or with a milky oil that trashes your bottom end. its worth getting the issue addressed if it is a bad head gasket.

__________________
98 Mazda B4000 4x4 31" tires
Check out my off road youtube channel: https://www.youtube.com/c/aicoffroadvideo

Open the hood when it's dark outside with the engine idling. And it is damp.

I bet you see a light show as the plug wires arc to the other engine parts. Humidity will allow the insulation to fail, leading to misfire and arcing.
The fact that once the engine warms up, (and drys the plug wires) it runs ok points me to the plug wires. They dry out, quit conducting the spark to ground, and then things are back to normal.
You can try cleaning the outside of the wire with soapy water so the coating will stick, get them dry(oven?) and then spray them with a clear plastic Varathane or Krylon or similar. That may keep out the water/humidity that allows the wires to leak the spark to the engine.
tom

wat kind spark plug did u get??

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Fx4 levelII
enough^^ said
t-bar cranked 33x10.5x15 bfg all terrain ko2-15x8 pro comp 7031- blacked out headlight and corners mustang dome Westin brushguard March 2014 TOTM

I purchased whatever brand of spark plugs they were carrying at Advance Auto Parts. I experienced this issue (rarely) before purchasing the spark plugs, though.

To tomw0 - your theory seems to be the most practical because my radio for the past 3 weeks has read "protect" which it should only due if there is a short. I'm wondering if that radio issue is related to the rough driving.... This week I'll pop the hood at night and see what it does turned on!

I'm on my 3rd ranger. Each one eventually had these problems. So start with the easy stuff
-plugs, wires, & coil pack
-Carefully clean the MAF sensor with contact cleaner
-fuel filter, injectors
-Cam shaft synchronizer (I personally replace them @ the same time as the coil pack)

If you replace all these components and the bucking comes back (usually a month) you're looking @ the head gaskets. If you're going that far in the motor, might as well get the heads checked. After all it's a 92, and all of those components need to be replaced anyway. Good luck


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99 XLT Super Cab 4.0 OHV - Manual - 4wd - Live Axle Conversion - Interior & Exterior LEDs - Mustang Dome
97 XLT Regular Cab 2.3 - Auto - 2wd (R.I.P)

I always use motor craft plugs heard some people using different one having problems

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Fx4 levelII
enough^^ said
t-bar cranked 33x10.5x15 bfg all terrain ko2-15x8 pro comp 7031- blacked out headlight and corners mustang dome Westin brushguard March 2014 TOTM

that's true.
hi howard!

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1999 xlt 2.5l 5-speed Supercab 159k
83 diesel 2.2l na
06 F250 6.0l psd
{click for lol}